Paraffin & Frozen Sectioning
The Histology Research Core offers both paraffin and frozen sectioning based on your specific research needs. The staff at the core facility are experienced in sectioning multiple tissue types, including invertebrates and plants, as well as locating specific areas of interest within a given sample.
Aortic Valves
Plant Stem Section
Lymphovenous Valves
In histology, sectioning refers to the service of cleanly and consistently cutting paraffin embedded or frozen tissue into a thin slice. These thin slices are referred to as sections and are then mounted to a slide. There are two main categories of sectioning, referred to as paraffin or frozen sectioning.
Frozen Sectioning
Frozen sectioning is the procedure of cutting thin sections of frozen tissue and is conducted in a cryostat. While frozen sections are physically less stable than paraffin, they are especially superior in the preservation of antigenicity and lipid retention.
Paraffin Sectioning
Paraffin sectioning is the procedure of cutting thin slices of tissue that has been dehydrated and infiltrated with wax using specialized equipment. This tissue is then embedded in wax before being cut on a microtome. Paraffin sections are more physically stable and superior to frozen sections in maintaining tissue morphology with less damage. But due to the wax infiltration process, paraffin sections are not optimal for some staining processes.
The sections themselves can vary in thickness, measured by micrometers, and by how they are mounted to the slide. Sections can be cut and mounted in one of two methods: serial or serial interrupted sections.
Serial Sectioning
Definition
Serial sectioning is the procedure of collecting and mounting sections on a slide in the sequential order in which they were cut on the microtome. A ribbon refers to the sequence of connected sections pulled from the microtome.
Example Figure
Serial Interrupted Sectioning
Definition
Serial interrupted sectioning is the procedure of collecting multiple ribbons of sections, each at a different area within the tissue block. For example: ribbon one can be collected initially and then 200 microns are skipped before ribbon two is collected. This method of sectioning is ideal for capturing multiple areas within a tissue on a single slide.
With this method, sections are mounted on the slide so that the first section, closest to the label, is from the first ribbon collected from a block, the second section is from the second ribbon deeper in the block, and so on .
Example Figure
